1. Field of the Invention
The present invention relates to a personal authentication apparatus and a personal authentication method that register biometric information unique to each individual person, and obtain the person's biometric information anew when performing authentication, and check it against the registered biometric information to authenticate the person.
2. Description of the Related Art
Facilities and equipment that require personal authentication for the opening and closing entrance doors of rooms or buildings or operating information processing devices, for example, in order to improve security or protect privacy have proliferated in recent years. For such authentication, code numbers have been widely used traditionally. In recent years, more secure personal authentication methods are becoming widespread in which sensors are provided to detect some biometric information unique to every individual for performing personal authentication (see Japanese Patent Laid-Open No. 2003-85539, No. 2004-112172).
A problem with a code number is that, if it is known to other person, the person can readily impersonate the holder of the code number. In contrast, personal authentication that relies on biometric information, which varies from person to person, can significantly reduce threat of impersonation.
In a system in which biometric information is used for personal authentication, it is required to improve security.
As one of the techniques to improve security, a technique in which information used for authentication is divided into multiple parts and managed separately or permutated has been proposed (see Japanese Patent Laid-Open No. 2002-7349, No. 2002-312317, No. 2003-248660, No. 2003-331290).
The technique significantly improves security, as information used for authentication is divided into multiple parts and managed separately or permutated and correct information can only be restored by collecting separately managed parts of information or put the permutated order to the original order.
Even if information used for authentication is divided into multiple parts and managed separately or permutated, the authentication information can be rebuilt by putting the parts together or putting the permutated order to the original order. If someone who is seeking ways to steal the information is aware that the information is managed separately or permutated in the system, the system may not be completely secure.